With the development of wireless communication technology, radio resource is becoming more and more insufficient. To sufficiently utilize limited radio resource, for example radio resource having been allocated to some services but having not been sufficiently utilized may be dynamically utilized. More particularly, for a primary system having a right to use radio resource, radio resource having not been sufficiently utilized by the primary system may be allocated to un-licensed high priority secondary system and low priority secondary system without influencing the use by the primary system, such that the secondary systems may properly use licensed radio resource of the primary system without influencing the use of radio resource by the primary system.
However, how to more efficiently allocate spectrum resource to a low priority system without influencing the use of spectrum resource by a high priority system including a primary system is a technical problem desired to be solved in the field.